With the rapid development of communication technologies, more and more users use a mobile terminal. An existing control channel can only use a transmission mode of a distributed mode where only one user is supported to perform information transmission at a same time-frequency resource position, which is far from meeting requirements. Hence, an enhanced physical downlink control channel (ePDCCH) occurs.
Different from the conventional control channel which only supports the transmission mode of the distributed mode, the enhanced control channel may support the transmission mode of the distributed mode and a transmission mode of a localized mode, where the enhanced control channel which employs the transmission mode of the localized mode is able to support multiple users to perform information transmission simultaneously on a same time-frequency resource position, the capacity and performance requirements of the control channel are greatly satisfied.
In order to distinguish between a user, a cell, a channel and information transmitted on the channel etc, a scrambling operation is performed to to-be-transmitted information usually, that is, using a scrambling sequence to scramble the to-be-transmitted information and then sending. Thus, the to-be-transmitted information needs to be scrambled when simultaneous transmission for multiple users at a same time-frequency resource position is supported or when multiple transmission modes are used for information transmission, that is, performing an initialization configuration to a scrambling sequence so as to determine the scrambling sequence and applying the scrambling sequence to the to-be-transmitted information so as to distinguish between a user, a cell, a channel and/or information transmitted on the channel, etc.